A sensor system which senses the surroundings of the vehicle is understood to include radar sensors, lidar sensors, video-based or camera-based, fused sensors or other optical sensors. The sensors can emit and receive the information by means of the vehicle in question or obtain it via vehicle-to-vehicle communication or vehicle-to-infrastructure communication. Furthermore, the signals which describe the surroundings of the vehicle can be passed on to the infrastructure or to following vehicles via a satellite-supported and navigation-supported system.
U.S. Pat. No. 5,694,321, which is incorporated by reference, discloses a yaw moment closed-loop controller in which values for a steering angle, a driving speed, a yaw angle speed and a lateral acceleration of the vehicle are measured or determined, wherein a reference or setpoint yaw speed is determined as a function of the steering angle and of the driving speed on the basis of a mathematical reference model, and wherein the difference value between the actual yaw angle speed of the vehicle and the reference or setpoint yaw angle speed is determined. On the basis of the difference value, a torque variable is calculated which is used to define brake pressures which generate an additional yaw moment by means of the brakes of the vehicle. The content of U.S. Pat. No. 5,694,321 is a component of the present application.
With a steering torque assistance system, steering requests which are already compatible in accordance with the closed-loop driving stability control are passed on to the driver. With an actuator of an active front-wheel steering system, a wheel steering angle can be set for performing driving dynamics assistance independently of the driver. In this context, a course which does not correspond to the directional request predefined by the driver is not yet set.
The surroundings detection system such as, for example, “long range radar”, detects an object in the direction of travel. This is currently used as a comfort function for the driver for inter-vehicle distance control, but it also provides the possibility of detecting dangerous approaching of an object. In other known systems, the radar is already used in a low-speed range to detect dangerous approaching and to then suitably brake before the object. Other systems detect the hazard of collisions with an object by means of a suitable surrounding sensor system such as a radar sensor system, lidar sensor system and video sensor system, warn the driver, initiate automatic partial braking and finally decelerate as a function of the remaining time to the collision with the object with automatic full braking in order to prevent the collision or at least mitigate it. Further systems are concerned with measures after an initial accident.
A method for predicting a movement trajectory of an object which moves in road traffic. In addition, a device for predicting a movement trajectory of an object which moves in road traffic and is suitable for carrying out the method is disclosed. A method and a device for predicting movement trajectories of a vehicle for preventing a collision, in which method only the trajectories in which, owing to a combination of braking intervention and steering intervention, the forces occurring at the wheels of the vehicle are in the range which corresponds to the maximum force which can be transmitted to the road from the wheel are taken into account for the prediction of the trajectories. An automatic braking and/or steering intervention is carried out as a function of the trajectories which are calculated in advance.
The closed-loop control strategy of the closed-loop driving stability controller or yaw moment controller which is described at the beginning includes a series of compromises which ensures, on the one hand, extremely good stabilization of the vehicle for by far the most driving situations but, on the other hand, also prevents the closed-loop driving stability controller from intervening too early or too violently, which would lead to a restriction in the tolerated driving dynamics or to losses in the closed-loop control comfort. In particular with respect to the driving dynamics which can be achieved with the vehicle, high demands are made of the closed-loop driving stability controller to ensure that the interventions cannot lead to a reduction in a “sporty” driving style. In particular, closed-loop control thresholds of the driving dynamics controller have to be set in such a way that incorrect closed-loop control operations are avoided, which incorrect closed-loop control operations could occur as a result of roadway inclinations and sporty steering prescriptions on race tracks or mountainous roads.
As a result of the widening of closed-loop control thresholds of the closed-loop driving stability controller or the intentionally chronologically delayed intervention by the closed-loop driving stability controller into the brakes or the steering of the vehicle, driving dynamics problems, which could have been avoided with a very early intervention which exhausts all the possibilities can occur in critical situations.
A critical situation is here an unstable driving state in which, in an extreme case, the vehicle no longer follows the driver. The function of a closed-loop driving stability control operation is therefore to give, within the physical limits in such situations, the vehicle the driving behavior which is desired by the driver.